The kidneys of Kolkata
The morning sun fires silver slivers of light dancing over gentle ripples as the icon of West Bengal, a white-breasted kingfisher, displays its magnificent turquoise plumage, gliding effortlessly towards me as it searches for food. As far as I can see, there’s water and wildlife, yet I’m just three kilometres from the suburbs of the teeming megalopolis of Kolkata: population, more than 16 million.
These are the East Kolkata Wetlands, 250 interconnected shallow lakes spread over a 12,500-hectare site that supports a diverse ecosystem that includes 33 migratory birds, 20 mammals and 42 endemic species of fish. As you fly into the city, the wetlands are difficult to miss, located directly south of the runway. Their sheer size is startling, taking up nearly a third of the total urban area. Sadly, once on the ground, few visitors bother to visit, and finding a taxi driver who knows their location is no easy task.
The very existence of this incongruous oasis is surprising enough, but even more surprising is the fact that this area of palpable natural beauty represents the world’s largest natural sewage treatment plant. For the past 100 years, the communities living in and around the wetlands have been inadvertently cleaning the millions of litres of organic waste produced by Kolkata’s citizens.
And nobody realised that they were doing it until 1980, when a government engineer serendipitously stumbled across the area. The West Bengal state government had assigned Dr Dhrubajyoti Ghosh the task of scouring the country to find a suitable model on which Kolkata could base a new sewage treatment system. ‘Little did I know I would never have to leave the confines of Kolkata,’ says the softly spoken Ghosh. ‘At the time, no-one in the city really knew what happened to sewage here, so I decided to follow it, and I arrived here.’
When he communicated his findings to his mentor, Professor Richard Meyer of the University of California, Berkeley, the eminent ecologist replied: ‘If you can be there for the next ten years of your life, you will have an impact on history.’ Nearly 30 years later, there has barely been a day when Ghosh hasn’t set foot in the wetlands.
Natural sewer
The lakes themselves, known locally as bheris, are relatively young, having formed 350 years ago as an overspill from the Bidyadhari, a tidal river that flowed into the Bay of Bengal. Originally, they were part of a vast saline area, but then a buildup of silt over the next 250 years caused the river to change course so dramatically that, by 1900, it had ceased to flow. Without the regular influx of sea water, the wetlands gradually became less and less saline.
Within this area of shallow fresh water were numerous now-isolated populations of various fish species that, over time, cross-bred, creating a unique ecosystem. This coincided with the creation by the British of the city’s first sewage channels, which, because of the land’s natural topography, flowed eastwards into the wetlands. Through their own ingenuity, the resident fishermen designed an intricate network of sluices and lakes to deal with the new inflow of wastewater.
Using techniques that are still in use today, the amount of organic waste entering each pond is controlled by a system of gates and bamboo sieves. As the sewage enters the fish ponds, it’s digested by bacteria, taking in oxygen and producing carbon dioxide. The introduction of carbon dioxide and nutrients enables algae to thrive, and this, in turn, provides a plentiful food source for the fish.
‘People here have developed a unique technology; it’s a completely natural cycle not seen in any other city,’ says Ghosh. ‘The greatest irony is that it’s here in Kolkata.’ And the role of the wetlands doesn’t end at dealing with the city’s sewage. More than 100,000 people are directly and indirectly reliant on them for their livelihood – each day, more than 30 tonnes of fish are caught and 150 tonnes of vegetables harvested: the staple ingredients of the West Bengali diet.
Most families have lived here for generations. It comes as no surprise that whatever their religious beliefs, everyone pays their respects to two locally worshipped dieties: Bombibi, the goddess of nature, and Makaltahkur, the protector from natural hazards.
However, the main threat to the wetlands doesn’t come from angry gods, but the rapidly expanding Indian economy. ‘The insouciance by the authorities to properly manage the wetlands could threaten their long-term future,’ says Dr Dipayan Dey, the founder of environmental NGO Safeinch and a charismatic nature lover who, since first setting foot in the wetlands two years ago, has been unable to tear himself away.
Dey was propelled into action when the wetlands’ status under the Ramsar Convention on the conservation of wetlands was nearly withdrawn because the government of West Bengal failed to come up with a cohesive plan to clean up a rubbish dump using a US$1.5million grant provided by the Asian Development Bank. ‘As the city relies on the wetlands to treat its sewage, the city needs to respect the laws of science, which rule the cleansing process,’ Dey says.
The main problem is the accelerated aggregation of silt on the bottom of ponds, a side effect of industrial expansion in the region. Although dumping industrial waste into the organic sewage channel is illegal, monitoring by the authorities has been ineffective, according to Dey. ‘The problem is that nobody is aware of how important a role the wetlands play,’ he says. ‘If we lose this area, the livelihoods of the people will be lost, the water table will fall and the raw sewage will go untreated.’
Many ponds have already lost 20 per cent of their depth; as a result, fish stocks have suffered. Frustratingly, the lack of infrastructure makes access for lorries to remove the silt almost impossible.
Hot property
The other main concern is the threat of property developers looking for new sites. Although Kolkata’s population growth rate is the lowest among India’s million-plus cities, it’s still spreading. Naturally, developers are going where land is cheap and seemingly in abundance. At present, the ponds are being infilled and developed at a rate of about one per cent a year. ‘Being so close to the city is their beauty, but it might ultimately be their downfall,’ Ghosh laments. ‘This is the kind of place where money is your enemy.’
In a bid to capture the hearts and minds of the urban population, and to provide an alternative income for the wetlands’ communities, Safeinch has launched an ecotourism initiative backed by a £20,000 grant from the British government’s Department for International Development. It aims to encourage visitors to the area by providing facilities such as covered seating, footpaths and fresh drinking water. ‘It’s about raising awareness among the decision makers in our society, the high fliers who can make a difference,’ says Chiranjeet Chatterjee, the group’s community development officer.
On a visit to the wetlands, the thread that links everyone you meet is a deep-rooted passion and love for this unique environment, an oasis of tranquillity in a desert of chaos.
December 2010
These are the East Kolkata Wetlands, 250 interconnected shallow lakes spread over a 12,500-hectare site that supports a diverse ecosystem that includes 33 migratory birds, 20 mammals and 42 endemic species of fish. As you fly into the city, the wetlands are difficult to miss, located directly south of the runway. Their sheer size is startling, taking up nearly a third of the total urban area. Sadly, once on the ground, few visitors bother to visit, and finding a taxi driver who knows their location is no easy task.
The very existence of this incongruous oasis is surprising enough, but even more surprising is the fact that this area of palpable natural beauty represents the world’s largest natural sewage treatment plant. For the past 100 years, the communities living in and around the wetlands have been inadvertently cleaning the millions of litres of organic waste produced by Kolkata’s citizens.
And nobody realised that they were doing it until 1980, when a government engineer serendipitously stumbled across the area. The West Bengal state government had assigned Dr Dhrubajyoti Ghosh the task of scouring the country to find a suitable model on which Kolkata could base a new sewage treatment system. ‘Little did I know I would never have to leave the confines of Kolkata,’ says the softly spoken Ghosh. ‘At the time, no-one in the city really knew what happened to sewage here, so I decided to follow it, and I arrived here.’
When he communicated his findings to his mentor, Professor Richard Meyer of the University of California, Berkeley, the eminent ecologist replied: ‘If you can be there for the next ten years of your life, you will have an impact on history.’ Nearly 30 years later, there has barely been a day when Ghosh hasn’t set foot in the wetlands.
Natural sewer
The lakes themselves, known locally as bheris, are relatively young, having formed 350 years ago as an overspill from the Bidyadhari, a tidal river that flowed into the Bay of Bengal. Originally, they were part of a vast saline area, but then a buildup of silt over the next 250 years caused the river to change course so dramatically that, by 1900, it had ceased to flow. Without the regular influx of sea water, the wetlands gradually became less and less saline.
Within this area of shallow fresh water were numerous now-isolated populations of various fish species that, over time, cross-bred, creating a unique ecosystem. This coincided with the creation by the British of the city’s first sewage channels, which, because of the land’s natural topography, flowed eastwards into the wetlands. Through their own ingenuity, the resident fishermen designed an intricate network of sluices and lakes to deal with the new inflow of wastewater.
Using techniques that are still in use today, the amount of organic waste entering each pond is controlled by a system of gates and bamboo sieves. As the sewage enters the fish ponds, it’s digested by bacteria, taking in oxygen and producing carbon dioxide. The introduction of carbon dioxide and nutrients enables algae to thrive, and this, in turn, provides a plentiful food source for the fish.
‘People here have developed a unique technology; it’s a completely natural cycle not seen in any other city,’ says Ghosh. ‘The greatest irony is that it’s here in Kolkata.’ And the role of the wetlands doesn’t end at dealing with the city’s sewage. More than 100,000 people are directly and indirectly reliant on them for their livelihood – each day, more than 30 tonnes of fish are caught and 150 tonnes of vegetables harvested: the staple ingredients of the West Bengali diet.
Most families have lived here for generations. It comes as no surprise that whatever their religious beliefs, everyone pays their respects to two locally worshipped dieties: Bombibi, the goddess of nature, and Makaltahkur, the protector from natural hazards.
However, the main threat to the wetlands doesn’t come from angry gods, but the rapidly expanding Indian economy. ‘The insouciance by the authorities to properly manage the wetlands could threaten their long-term future,’ says Dr Dipayan Dey, the founder of environmental NGO Safeinch and a charismatic nature lover who, since first setting foot in the wetlands two years ago, has been unable to tear himself away.
Dey was propelled into action when the wetlands’ status under the Ramsar Convention on the conservation of wetlands was nearly withdrawn because the government of West Bengal failed to come up with a cohesive plan to clean up a rubbish dump using a US$1.5million grant provided by the Asian Development Bank. ‘As the city relies on the wetlands to treat its sewage, the city needs to respect the laws of science, which rule the cleansing process,’ Dey says.
The main problem is the accelerated aggregation of silt on the bottom of ponds, a side effect of industrial expansion in the region. Although dumping industrial waste into the organic sewage channel is illegal, monitoring by the authorities has been ineffective, according to Dey. ‘The problem is that nobody is aware of how important a role the wetlands play,’ he says. ‘If we lose this area, the livelihoods of the people will be lost, the water table will fall and the raw sewage will go untreated.’
Many ponds have already lost 20 per cent of their depth; as a result, fish stocks have suffered. Frustratingly, the lack of infrastructure makes access for lorries to remove the silt almost impossible.
Hot property
The other main concern is the threat of property developers looking for new sites. Although Kolkata’s population growth rate is the lowest among India’s million-plus cities, it’s still spreading. Naturally, developers are going where land is cheap and seemingly in abundance. At present, the ponds are being infilled and developed at a rate of about one per cent a year. ‘Being so close to the city is their beauty, but it might ultimately be their downfall,’ Ghosh laments. ‘This is the kind of place where money is your enemy.’
In a bid to capture the hearts and minds of the urban population, and to provide an alternative income for the wetlands’ communities, Safeinch has launched an ecotourism initiative backed by a £20,000 grant from the British government’s Department for International Development. It aims to encourage visitors to the area by providing facilities such as covered seating, footpaths and fresh drinking water. ‘It’s about raising awareness among the decision makers in our society, the high fliers who can make a difference,’ says Chiranjeet Chatterjee, the group’s community development officer.
On a visit to the wetlands, the thread that links everyone you meet is a deep-rooted passion and love for this unique environment, an oasis of tranquillity in a desert of chaos.
December 2010
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